Characterization of aliphatic amine 1,4-diazobicyclo (2,2,2) octane-induced stimulation of beet spinach thylakoid...

Electron transport activity of beet spinach thylakoids was enhanced in the presence of aliphatic amine, DABCO (1,4-diazobicyclo (2,2,2) octane), a hydrophilic proton trapping agent. The extent of stimulation was pH-dependent and similar to the effect of the uncoupler ammonium chloride on electron transport. The stimulation of whole-chain (H2O-->MV) electron transport activity was observed only at high (rate-saturating) light intensity. The light-induced proton uptake coupled to electron transport of thylakoid was also arrested by DABCO, suggesting that DABCO uncouples thylakoid phosphorylation by proton trapping.